With the intensive development of cities and the emergence of a great number of urban high-rise buildings, an elevator as a vertically running transportation means in the high-rise buildings has already been inseparable to daily life of people. Accordingly, the safety and the reliability of the elevator have already been widely concerned by people.
An elevator brake device in the operation of the elevator is one of important components for safe and reliable operation of the elevator. However, a traditional brake device of an elevator traction machine realizes the opening and closing of the brake by virtue of electromagnets. When the vertically-running elevator is in a static state, no current flows through electromagnetic coils in a traction motor and the brake device, and at this moment, since there is no attractive force between electromagnetic iron cores, brake shoes in the brake tightly embrace brake wheels under the pressure action of brake springs so as to ensure that the motor cannot rotate; and when the traction motor is energized to rotate, the coils in the brake electromagnets are also energized, the electromagnetic iron cores can be rapidly magnetized and attracted to drive brake arms and the brake springs, so that the brake shoes are unfolded to be completely separated from the brake wheels, and the elevator can run. However, since a brake device can keep a release state only when being continuously energized if the vertically-running elevator runs normally, the coils are liable to heat, and a great amount of useless-work electric energy is wasted; the elevator as one of the largest “power consumption tigers” of modern buildings consumes a great amount of energy, and people at all sectors of society have weak consciousness of the energy conservation of the elevator. Therefore, the energy-saving work of the elevator is urgent.